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Adding HClO4 to [(BnTPEN)MnIII–OO]+ in MeOH generates a short-lived MnIII–OOH species, which converts to a putative MnV＝O species. The potent MnV＝O species in MeCN oxidizes the pendant phenyl ring of the ligand in an intramolecular fashion. The addition of benzene causes the formation of (BnTPEN)MnIII-phenolate. These findings suggest that high valent Mn species have the potential to catalyze challenging aromatic hydroxylation reactions. [ABSTRACT FROM AUTHOR]

Lewis acid‐bound high valent Mn‐oxo species are of great importance due to their relevance to photosystem II. Here, we report the synthesis of a unique [(BnTPEN)Mn(III)−O−Ce(IV)(NO3)4]+ adduct (2) by the reaction of (BnTPEN)Mn(II) (1) with 4 eq. ceric ammonium nitrate. 2 has been characterized using UV/Vis, NMR, resonance Raman spectroscopy, as well as by mass spectrometry. Treatment of 2 with Sc(III)(OTf)3 results in the formation of (BnTPEN)Mn(IV)−O−Sc(III) (3), while HClO4 addition to 2 forms (BnTPEN)Mn(IV)−OH (4), reverting to 2 upon Ce(III)(NO3)3 addition. 2 can also be prepared by the oxidation of 1 eq. Ce(III)(NO3)3 with [(BnTPEN)Mn(IV)=O]2+ (5). In addition, the EPR spectroscopy revealed the elegant temperature‐dependent equilibria between 2 and Mn(IV) species. The binding of redox‐active Ce(IV) boosts electron transfer efficiency of 2 towards ferrocenes. Remarkably, the newly characterized Mn(III)−O−Ce(IV) species can carry out O‐atom and H‐atom transfer reactions. [ABSTRACT FROM AUTHOR]

Adding HClO 4 to [(BnTPEN)Mn III -OO] + in MeOH generates a short-lived Mn III -OOH species, which converts to a putative Mn V O species. The potent Mn V O species in MeCN oxidizes the pendant phenyl ring of the ligand in an intramolecular fashion. The addition of benzene causes the formation of (BnTPEN)Mn III -phenolate. These findings suggest that high valent Mn species have the potential to catalyze challenging aromatic hydroxylation reactions.

A simple and atom economic protocol for the construction of C-X/C-C bonds via catalytic aminium radical-cation salt (Magic Blue)-initiated S N 2-type nucleophilic ring-opening transformations of racemic and nonracemic aziridines with different hetero and carbon nucleophiles to afford various amino ethers, thioethers, and amines in up to 99% yield, and with perfect enantiospecificity for some substrates but reduced ee with others (for nonracemic aziridines), is developed. This aminium radical-cation salt-initiated, S N 2-type nucleophilic ring-opening strategy, along with various cyclization protocols, is employed to synthesize various biologically significant compounds.

Lewis acid-bound high valent Mn-oxo species are of great importance due to their relevance to photosystem II. Here, we report the synthesis of a unique [(BnTPEN)Mn(III)-O-Ce(IV)(NO 3 ) 4 ] + adduct (2) by the reaction of (BnTPEN)Mn(II) (1) with 4 eq. ceric ammonium nitrate. 2 has been characterized using UV/Vis, NMR, resonance Raman spectroscopy, as well as by mass spectrometry. Treatment of 2 with Sc(III)(OTf) 3 results in the formation of (BnTPEN)Mn(IV)-O-Sc(III) (3), while HClO 4 addition to 2 forms (BnTPEN)Mn(IV)-OH (4), reverting to 2 upon Ce(III)(NO 3 ) 3 addition. 2 can also be prepared by the oxidation of 1 eq. Ce(III)(NO 3 ) 3 with [(BnTPEN)Mn(IV)=O] 2+ (5). In addition, the EPR spectroscopy revealed the elegant temperature-dependent equilibria between 2 and Mn(IV) species. The binding of redox-active Ce(IV) boosts electron transfer efficiency of 2 towards ferrocenes. Remarkably, the newly characterized Mn(III)-O-Ce(IV) species can carry out O-atom and H-atom transfer reactions., (© 2023 Wiley-VCH GmbH.)